I also find the resume cruise control at whatever speed you happened to brake at, annoying. However, I learn to live with it and just have it automatically resume to speed limit speed by tapping on the speed limit icon on the dash (Model 3 or Model X), then make adjustments from there. So instead of at 25mpg and scroll (M3), or flip lever (X) all the way back to 65mph. Tap the icon and it'll set it at the speed limit and go from there. Annoying yes, but as others have said, what if you intended to brake and forgot that smart cruise control is on. could lead to dangerous situations.
-ThinkMac-